180 BCLIPSES Views of other astronomers regarding the calculation of a lunar eclipse: 74. Others give instruction in the lunar eclipse without the use of the ten Rsines, because it causes little difference in the result (and is simpler). There (i.e., in the rule stated by them) the sparsa- and mokṣa-sthityardhas arising from (the Moon's latitude for) the time of opposition of the Sun and Moon (lit. middle of the eclipse) should be operated upon by the method of successive approximations. Details of the process of successive approximations referred to above: 75-76. Multiply the (true) daily motion (of the Moon) by the time (in ghatis) of the sthityardha and divide the product by 60. Subtract the quotient from or add that to the Moon's (true) longitude for the time of opposition (of the Sun and Moon), according as it is the first or last contact. From that find out the Moon's latitude; and therefrom (again) calculate the sthityardha. (In this way repeat the above process again and again until two successive approximations agree). This is the process of successive approximations. Similar again is the process of (determining) the (sparsa- and mokṣa-) vimar- dardhas.¹ A rule relating to the direction of the Moon's latitude to be taken in the projection of a lunar eclipse: 77. While projecting an eclipse (of the Moon), the best amongst the learned should take the direction of the Moon's latitude to be north when it is south, and south when it is north. ¹ For details see our notes on Lbh, iv. 10-12. The rule stated here is found also in BrSpSi, iv. 8-9; SiDV, I, iv. 14-16; Siśe, v. 12-13; Sisi, I, v. 12-13.
